Correction device for correcting acceleration data, method therefor, program therefor, recording medium containing the program and navigation guide device

Abstract

A correction device determines, by calculation, a real acceleration based on output from a velocity sensor 4. GPS mediated signal receiving portion 2 receives radio navigation waves from plural GPS satellites. The device detects a frequency change of the radio waves evoked as a result of Doppler effect, acquires horizontal and vertical velocity components based on the frequency change, and determines, by calculation, a gradient angle. Then, the device determines, by calculation, the gravitational acceleration sine of the gradient angle (G. sin θ). The device adds the real acceleration and the gravitational acceleration sine of the gradient angle (G. sin θ) to provide a theoretical acceleration of the acceleration sensor. The device divides the theoretical acceleration of the acceleration sensor with the sensitivity of the acceleration sensor 6, and subtracts the result from output from the acceleration sensor 6, to provide a right offset value. Then, the sequentially obtained offset values are averaged to give an updated offset value. This process makes it possible to readily obtain a right offset value even during the driving of the mobile body.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a correction device for correcting acceleration data provided based on output from an acceleration sensor which detects the acceleration of a mobile body, by determining via calculation an offset value of the acceleration sensor and correcting the output based on the offset value, correction method therefor, correction program therefor, recording medium for recording the program, and navigation guide device.[0003]2. Description of Related Art[0004]The conventional well-known system for guiding the navigation of a mobile body such as a motor vehicle, aircraft and ship includes navigation guide systems. The navigation guide system obtains information regarding the current position of a mobile body, relates the current position with map information, and plots the current position on a map. Specifically, the navigation guide system determines the current position of a mobile body, its travel...

AI Technical Summary

Benefits of technology

[0007]In a view of above, a principal object of this invention is to provide a correction device for correction an acceleration sensor by readily determining an offset value of the sensor and correction output from the sensor based on the offset value, correction method therefor, correction program therefor, recording medium for recording the program, and navigation guide device.

Problems solved by technology

As described above, with the conventional navigation guide system, to obtain an offset value of an acceleration sensor, it is necessary to keep a mobile body to which the sensor is attached motionless on a horizontal plane and to read output from the sensor, which requires complicated operation.

Thus, to ensure the rightness of the acceleration data acquired based on output from the acceleration sensor, it is necessary to often check the sensor and obtain a right offset value during the prolonged use of the mobile body, which requires complicated operation.

Such an operation when performed often may hinder the proper operation of the mobile body.

Moreover, if owing to a certain situation, checking of the sensor were impossible, the sensor would be left unchecked, and the navigation guide system could not achieve the proper navigation guide assigned to it.

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